When George Bush took office in 2000, the U.S. public debt—the amount the Federal Government owes in treasury bonds—was $3.4 trillion. When George Bush left office, it was $5.8 trillion. For all of his misspending, it pales compared to our current situation. Today, as of this writing, with Obama holding office for a mere 2 years, the public debt stands at $9.2 trillion.
The average tax payer owes around $7000 for each trillion dollars of government spending, so Obama has spent over $20,000 for each tax paying citizen in two years. Do we have $20,000 per head worth of a better country? I guess that is a personal decision each citizen needs to make.
This is what the government owes. It is different than the gross national debt, which is in the neighborhood of $14 trillion—this is what we always see on the national debt clock. The extra $5 trillion is intra-governmental debt, or debt that will one day need to be taken in order to meet Social Security and Medicare obligations. But to the degree the federal government functions as a single economic entity, which it does, it is not debt that actually exists, not yet, and truth be told, anything could still happen regarding Social Security and Medicare obligations.
The public debt is what the government actually needs to pay back today, and I think is overall the more sensible number to look at than gross debt when considering government solvency.
$9.2 trillion is a lot of money, which leaves a lot of question about the government's ability to pay it back. GDP estimates are around $14 trillion for the U.S., and yearly tax revenues (first column in the link) are in the $2.5 trillion range for the federal government. If the intest on the public debt stands at 5% on average, which I think overestimates it given how very low rates are now, then yearly interest payments on $10T would be $500B, which sits pretty manageably within $2.5 trillion of revenues, provided revenues hold constant and do not recede.
I'm going to guess the government could at least double the debt before default (or hyperinflation) would be a genuine concern. To the degree that government spending draws money away from private markets and burdens the productive capacity of the economy—the recent exponential growth of debt is still unwelcome.